user
Describe in a few sentences what is a computer virus.

assistant
A computer virus is a type of malicious software designed to replicate itself and spread from one computer system to another. It can cause harm to computer systems by destroying data or causing system errors. Viruses can also be used to gain unauthorized access to personal and/or private information. In some cases, viruses can even infiltrate and take control of parts of an operating system or site, allowing the creator to use it for their own malicious intent. In order to protect computer systems from viruses, users should ensure they have up-to-date virus protection software on their systems.